About the

About the Kuiper Airborne Observatory

Basic information about the KAO

The Gerard P. Kuiper Airborne Observatory (KAO) is a national facility operated by the National Aeronautics and Space Administration to support research in infrared astronomy. The observation platform is a highly modified C-141A jet transport aircraft with a range of 6000 nautical miles, capable of conducting research operations to 45000 feet (14 km).

The KAO's telescope is a conventional Cassegrain reflector with a 36-inch (91.5 cm) aperture, designed primarily for observations in the 1 to 500 micron spectral range. The telescope looks out the left side of the aircraft at an elevation of between 35 and 75 degrees.

The KAO is based at the Ames Research Center (aerial view - 583 KB) at Moffett Field, California (near San Jose, CA). It is operated as a facility for scientists whose proposals have been deemed suitable and have been approved by NASA. Those scientists perform research with scientific instruments which have often been developed especially for use on the aircraft. Each instrument may be installed on the aircraft for a few days to several weeks, allowing multiple flights and investigators using the same instrument.

What the KAO Does (and How It Does It)

The KAO performs astronomical observations analogous to those made in ground-based or space-based telescopes. The KAO's observing capabilities fill a unique niche in astronomical science, however. Its flight capability allows it to rise above much of the water vapor in the earth's atmosphere (allowing observations of infrared radiation which is blocked before reaching ground-based facilities), as well as travel to almost any point on the earth's surface for an observation. At the same time, in between flights the facility is ground-based, allowing systems development, maintenance, and repair.

To perform astronomy while in flight, a number of systems must work together to provide a stable observation platform. Several sub-systems or steps are involved in this process. They include:

- the aircraft autopilot
- the vibration isolation system
- the spherical air bearing
- the gyro-stabilization system
- the video star tracker
Each of these is described in further detail, and the use of the systems as a unit provides a lesson on KAO Telescope Operations.

Putting it Together: KAO Telescope Operations

During taxi, takeoff, and ascent, aircraft vibrations are transmitted with little damping throughout the telescope structure. About five to ten minutes before observing is to begin, the Telescope Operator at the Main Console begins activating the telescope stabilization system. First, the four vibration isolators are activated. The telescope is then "up on isolators" and partly insulated from aircraft vibration. After airflow around the air-bearing is started, the telescope may be "uncaged". Linear uncaging allows the telescope to be "floating" on the air-bearing. Rotary uncaging permits slewing of the telescope to the desired elevation angle. Unless balance is being checked, the telescope will be gyro-stabilized when it is floating. The telescope must be caged before the aircraft turns onto a new heading.

The telescope aperture door is normally kept closed until the aircraft is at 35,000 feet or higher. After the flight crew have leveled off the aircraft at the initial assigned altitude, the door is raised to expose the telescope. Opening the door takes about two minutes. After the Mission Director receives verification from the flight deck that the aircraft will remain level and is on the correct heading, the Telescope Operator may uncage the telescope and transfer control from the Main Console to the forward joystick and Tracker Console. The Tracker Operator or the Investigator will then have control of the telescope for fine pointing.

A Brief History of the KAO

The aircraft began as a Lockheed Model L300 Starlifter jet transport, originally configured as a prototype commercial version of the U.S. Air Force C-141A. The telescope system was designed and built by the Fecker Systems Division of the Owens-Illinois Corporation. The telescope cavity was designed and installed by Lockheed Aircraft Services in May 1973. Research operations began in February, 1974, and the facility was dedicated as the Gerard P. Kuiper Airborne Observatory (KAO) in May, 1975.

The information on this page was taken from the Kuiper home pages by Florentino.
Here is information about the original KAO WWW Authors

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